Parliament released his arch-nemesis, former prime minister Yulia Tymoshenko, who walked free from the hospital where she had been jailed, completing a radical transformation in the former Soviet republic of 46 million people.
The apparent toppling of the pro-Russian leader, after bloodshed in Kiev that saw 77 people killed and the centre of the capital transformed into an inferno, looks likely to pull Ukraine away from Moscow's orbit and closer to Europe. It is also a stark reversal for Russian President Vladimir Putin's dream of recreating as much as possible of the Soviet Union in a new Eurasian Union, in which Moscow had counted on Yanukovich to deliver Ukraine as a central member.
Members of the Ukrainian parliament, which decisively abandoned Yanukovich after this week's bloodshed, stood, applauded and sang the national anthem after it declared the president constitutionally unable to carry out his duties and set an early election for May 25.
"This is a political knockout," opposition leader and retired world boxing champion Vitaly Klitschko said.
Moments later, opposition leader Tymoshenko, 53, waved to supporters from a car as she was driven out of the hospital in the northeastern city of Kharkiv, where she has been treated for a bad back while serving a seven-year sentence since 2011.
In a television interview which the station said was also conducted in Kharkiv, Yanukovich said he would not resign or leave the country, and called decisions by parliament "illegal".
"The events witnessed by our country and the whole world are an example of a coup d'etat," he said, comparing it to the rise of the Nazis to power in Germany. He said he had come under fire. "My car was shot at. I am not afraid. I feel sorrow for my country," he told UBR television.
Ukraine's parliamentary speaker said Yanukovich had been prevented from boarding a plane to Russia and was now in the Donetsk region. Despite his defiance, the dismantling of his authority seemed all but complete, with his cabinet promising a transition to a new government, the police declaring themselves behind the protesters and his arch-rival Tymoshenko going free.
At the president's headquarters, Ostap Kryvdyk, who described himself as a protest commander, said some protesters had entered the offices but there was no looting. "We will guard the building until the next president comes," he said. "Yanukovich will never be back."
The grounds of Yanukovich's residence outside Kiev were being guarded by "self-defence" militia of protesters.
"The cabinet of ministers and ministry of finance are working normally," the cabinet said in a statement. "The current government will provide a fully responsible transfer of power under the constitution and legislation."
Military and police leaders said they would not get involved in any internal conflict. The interior ministry responsible for the police said it served "exclusively the Ukrainian people and fully shares their strong desire for speedy change".
"The organs of the Interior Ministry have crossed to the side of the protesters, the side of the people," said new interior minister Arsen Avakov.
Yanukovich, who enraged much of the population by turning away from the European Union to cultivate closer relations with Russia three months ago, made sweeping concessions in the deal brokered by European diplomats on Friday after days of street battles.
But the deal, which called for early elections by the end of the year, was not enough to satisfy pro-Europe demonstrators on Independence Square, known as the Maidan, or "Euro-Maidan", who wanted Yanukovich out immediately in the wake of the bloodletting.
Yesterday, the speaker of parliament, a Yanukovich loyalist, resigned and parliament elected Oleksander Turchynov, a close ally of Tymoshenko, as his replacement.
"Today he left the capital," Klitschko said of Yanukovich at an emergency session of parliament. "Millions of Ukrainians see only one choice - early presidential and parliamentary elections." Two protesters in helmets stood at the entrance to the president's
Kiev office. Asked where state security guards were, one, Mykola Voloshin, said: "I'm the guard now."
While events moved quickly in the opposition's favour there were still worrying signs that the country will face political instability with the ultra-radical Ukrainian opposition group Right Sector insisting it would continue protests in Kiev.
"The Right Sector will not disperse," the group, one of several that is involved in the protests in Kiev, said in a written statement. "It is not the time to celebrate. Now we must be more united than before."
Reaction to events in Ukraine differed in Washington and Moscow.
Putin's envoy to Ukraine yesterday criticised the EU ministers who helped broker a peace deal in Kiev.
"I do not understand, frankly, how after recognising the legitimacy of President Yanukovich, the parliament, all the state structures, my European colleagues can then come to Kiev and go to the nationalist-revolutionary and terrorist Maidan and say there - down with the government they recognised," Russian envoy Vladimir Lukin said.
The deal between Russia-backed Yanukovich and the opposition was brokered by the foreign ministers of France, Poland and Germany.
Washington by contrast welcomed the release of Tymoshenko and pledged to work with Russia and European and international organisations to support Ukraine.
"We have consistently advocated a de-escalation of violence, constitutional change, a coalition government, and early elections, and today's developments could move us closer to that goal," the White House said in a statement.
British Foreign Secretary William Hague said: "Events in the last 24 hours show the will of Ukrainians to move towards a different future, and ensure that the voices of those who have protested courageously over several months are heard. We will work closely with our EU partners in support of a new government in Ukraine, as and when that is formed."